Such locking devices are used, for example, in shifting devices for actuating transmissions in motor vehicles in order to indicate the shift positions selected by the driver by means of a gearshift lever. The gearshift lever is fixed in the shift positions by means of a locking device in relation to a gearshift housing and it indicates to the driver that a desired shift position has been reached. Due to tolerances related to the design and manufacture, the mounting of the movable parts of the locking devices, especially a locking pin, has a clearance, which leads to an inaccurate and fuzzy indication of the shift position by the gearshift lever. Furthermore, this clearance may lead to an undesired noise generation during travel. Centering devices are used to avoid the clearance between the locking pin and its mount.
Such a centering device is disclosed in WO 02/061 522, where an elongated sleeve, which surrounds the pin for the locking mechanism and is in functional connection with the bracket, is used for centering. The pin and the sleeve are arranged in a recess of the bracket and are in connection with one another via a compression spring. The sleeve is slotted in parallel to its longitudinal axis toward the head of the pin and thus forms a plurality of tongue-like and flexible sections. In the area of the opening of the recess, the sleeve has, furthermore, a conical area, which is in contact with a likewise conical area on the bracket. The head of the pin cooperates, in turn, with the surface of a fixed contour and locks into depressions in the surface. In case of contact between the pin and the surface of the stationary contour, the compression spring transmits a compressive force directed into the recess onto the sleeve, and the sections of the sleeve are bent over the conical areas in the direction of the central longitudinal axis. The sections of the sleeve press by a plurality of the pins and thus center the latter in relation to the central longitudinal axis.
The components that have a complicated shape and require much space for their installation are especially disadvantageous in the embodiment according to WO 02/061 522. The sleeve used, in particular, required a comparatively large diameter for the recess in the bracket as well as great depth of the recess, because the sleeve is arranged around the pin and the individual sections require a certain length in the axial direction for the necessary bending. Furthermore, clamping does not necessarily take place for the centering over the entire circumference of the pin, but in a punctiform manner only and over a relatively small pressing area, which may lead to premature wear phenomena in the form of pressure marks and furrows on the pin in the unfavorable case. Due to the only punctiform effect of the slotted sections, the pin is not absolutely centered in relation to the central longitudinal axis of the recess if the sleeve was manufactured with a defect. Furthermore, centering always takes place in the area of the opening of the recess, because the sleeve is supported here at the bracket. Moreover, it is necessary for the satisfactory function of the centering device that the sleeve be manufactured from a plastic in order to satisfactorily ensure the necessary bending of the sections. Selection from among the possible materials that can be used is thus greatly limited.
Another essential disadvantageous aspect of the embodiment according to WO 02/061 522 is the possible squeezing of the sleeve during the shifting operation or in case of abuse. The shifting forces act on the pin at right angles to the longitudinal axis thereof during the shifting operation, as a result of which the shifting forces are transmitted completely via the sleeve, especially in case of abuse, and there is a risk of damage to the sleeve.